Insect growth regulating activity of a substituted urea compound XRD-473 (OMS 3031) was evaluated against the target species viz.Culex quinquefasciatus, Aedes aegypti, Anopheles stephensi and non target speciesToxorhynchites splendens. This compound inhibited the emergence of all these mosquito species with EI50 values of 9×10−5, 1·09×10−4, 2·22×10−4 and 2·14×10−4 mg (ai)/l respectively. Emergence inhibiting activity of XRD-473 was found to be more than fenoxycarb, and S 21149 against one or other species. In stagnant polluted water, the activity of the compound againstCulex quinquefasciatus was for shorter duration of 5 and 10 days at 0·02 and 0·2 kg(ai)/ha respectively whereas in clear water the activity was for longer duration i.e. 11 and 17 days at the same dosage. However, in drain the activity was negligible i.e. 12 days at 2 kg(ai)/ha. More than two weeks control ofAedes aegypti was obtained in cement tank at the treatment rate of 0·2 kg(ai)/ha whereas at the lower dose of 0·02 kg(ai)/ha this compound was effective for less than a week.